This invention pertains generally to medical instruments and more specifically to spinal implant insertion instruments for spinal fixation systems. Spinal rods or other stabilization devices for partially or fully immobilizing vertebral bones of the spinal column are typically anchored to the vertebrae via anchor members such as bone screws or hooks. The rods are connected to the anchor members by generally yoke-shaped coupling members that can be integral with or coupled to the anchor member the coupling members may be formed as separate components from the anchor member so that the anchor may pivot with respect to the coupling member. Generally these systems employ a compression or lock member (such as a threaded or non-threaded cap secured to the coupling member) that secures an elongate stabilization device, such as a spinal rod, within the coupling member.
Examples of coupling devices are disclosed in U.S. Utility patent application Ser. No. 11/839,843 and Provisional Applications 60/822,603 and 60/825,366, which disclose several different exemplary devices, especially pedicle screw devices and systems. These systems must be secured to bone using an anchor member, preferably a threaded shank forming a screw for rotatable insertion into the bone. These devices are commonly screwed into the pedicle region of a vertebra in order to secure a spinal rod or other stabilization member thereto. There remains a need, however, to provide improved tools for securing those systems to the spine.